Artificial board and process for preparing same



United States Patent Ofiice ,jj'itiil 1 2 350%,297 vention is made by condensing a hydrocarbon oil with an ARTIFICIAL BGARD AIID PROCESS FOR aldehyde in the P16861166 Of an acid catalyst. The hydropREpARING SAME carbon oil is a fraction containing substantial amounts Melvin E. ?eterlrin, Brookhaven, and Stewart S. Kurtz, of aromatic hydrocarbons. The boiling range of the oil Jrn, Merion Station, Pa., assignors to Sun Oil Com- 5 is from about 200 F. to 650 'F. Sources of the oil in- P y, P adelphia, Pa., a corporation of New J r y elude recycle streams from catalytic and thermal crack- NO Drawing File? 1961, 95,790 ing, fractions separated by distillation and solvent ex- 6 (CL260-9) traction and blended aromatic stocks. It is desirable This invention relates to improvements in artificial that the oil contain from 2 0-100% aromatic hydroboards bonded by heat and pressure from a filler and a 10 carbons, preferably from 25-50% aromatics. thermoplastic hydrocarbon resin. Paraformaldehyde is the preferred condensing agent In the past resins have been prepared from aromatic although formaldehyde, formalin, and other carbonyl petroleum fractions and formaldehyde in the presence of compounds can be used. an acid catalyst. When these resins are combined with Suitable condensation catalysts include formic acid, cellulose or lignocellulose fillers under heat and pressure, sulfuric acid, metal chlorides and hydrogen halides such the resulting molded shapes lack sufficient strength in as HR Fcrmic acid is preferred because of the high comparison with commercial materials such as Masonite. quality resin produced when it is used as catalyst.

The object of this invention is to provide a superior The reaction conditions employed in producing the artificial board having a petroleum resin binder. A parresin depend upon the catalyst and other factors. Genticular object ofthe invention is to provide ahigh strength 0 erfllly p g, temPeIamIeS 0f 80 t0 Pressures hardboard having a sawdust and/ or shredded paper filler. of atmospheric to 300 psig and oil-aldehyde molar We have found that additional strength is achieved by ratios of l.0:l.0 to :10 are suitable. The catalyst the addition of hexamethylenetetramine to the resin and can be present in amounts ranging from to 100% by filler prior to the molding operation. volume based on the aromatic oil feed.

Hexamethylenetetramine has been used previously as 25 Following condensation, the lower boiling fraction a hardening agent for thermosetting resins and with cerhaving a vapor temperature endpoint of from 800 to tain other resins as disclosed in US. Patent No. 2,418,- 950 F. at atmospheric pressure is distilled olf. Vacuum 293. With petroleum resins, however, the addition of distillation of 5 mm. to a vapor temperature endpoint of hexamethylenetetramine had no significant eflect-as from about 480 F. to 610 F. is preferable. will be seen from the examples appearing later in the dis- The resulting resin will have an initial boiling point of closure. We have discovered that when hexamethylenefrom SOD-950 F. and a ring and ball softening point tetramine is added in small amounts to mixtures of petoof SO-150 C. leum resins and a cellulose or lignocellulose-filler prior Table 1, below, shows the resins resulting from conto hot pressing, the resulting artificial board. product is densation in the presence of a formic acid catalyst at the stronger. conditions indicated. In all cases the reaction mixture The hydrocarbon resin component of the present inwas agitated with a motor driven stirrer.

7 TABLE -I Comparison of Runs at Various Temperatures and Pressures RUNS 0N PRESSURE REACTOR Products Reaction Run Chg. Soft Intermediate resin Final resin Total, No. Stk. 650 C.

Terran Pressure, Time,

B.R., Ringand Appear- B.R., Ringand Appearp.s.i.g. hrs F. b

Ml. F. ball, ance I Grams ance l enthalpies: OOOOOFI RUNS IN GLASS REACTOR AT ATMOSPHERIC PRESSURE v 8 10-3 1 102 Atm. 9 10-7 1 102 Atm.

11 650-814 31 814-930 64 5 C 23 930 118 6 E 6 E Z E30 iul. oildin rtealctor brought to temperature, then solution of (II-I20 in CHOOH (20 g./125 ml.=0.l6 g./m i. acid) added from blowcase.

ce ic aci on a yst. 11 Regular run in glass reactor; 3,000 mi. oil, 725 m1. acid, 120 g. paraiormaldehyde (0.16 gJml. acid). Data shown are actual-to provide comparison with pressure reactor runs.

d Boiling points are equivalent atomospheric" figures converted from vacuum distillation data. 8 See the following table:

mdM

Charge Type N d Gel aromatics Per- Per- Percent cent cent 0 A UN 01 10-3 Cat. gas oll 1. 4875 0. 8644 31. 9 23 22 55 12- (lo 1. 4987 0. 8791 48. 2 28 20 52 10-7 do 1. 4991 0.8753 41. 8 30 16 54 1 1, liquid; 2, viscous liquid; 3, soft plastic; 4, intermediate plastic; 5, hard plastic; 6, brittle. A, water white clear; B, light yellow clear; 0, yellow cleamlfideep yellow clear; E, brown; F, dark brown; G, black.

1 e mi.

The products in Table I above are divided into soft, intermediate and final resins. The final resins are used in making the artificial board of the invention. The final resins are obtained by Vacuum distillation and represent about 10-15 by volume of the total resin product. The table shows that the use of elevated temperatures and pressures (runs 1-7) speeds up the reaction considerably over low temperature operation at atmospheric pressure (runs 8 and 9).

The final resins are solid at room temperature and have a ring and ball softening point of from about 90- 150 C.

Other petroleum resins than those shown above can be used as the resin component of the artificial board of the present invention.

The resin is employed in amounts ranging from to 2- ing from 0.1 to 6% by weight, preferably from 1.0 to 4.5% by weight.

The hardboard of the present invention may be made by any of the many methods employed in molding operations of this type. Broadly speaking, the mixture to be molded is mixed to provide good distribution of the ingredients. The resin is usually ground to a fine powder prior to the mixing step. The mixture is then placed in the mold and heated while pressure is applied. Temperatures in the range of 250450 F. and pressures of 200 to 10,000 p.s.i. are suitable. A continuous process can be used if desired.

The following examples in Table II show the eifect of changing various components and conditions in making hardboard. The mold was the standard 2" x 6" x size used for making test blanks.

TABLE 11 Variable Study of Petroleum Resins in Wallboard Type Formztiarion Weight 28 C. 80 C. Per- Per- Per- Mold Mold Mold of modu- Bend Weight Loss modu- Variable cent of cent of cent of time temp. pressure chg. Variable lus of .001 (g.) lus of Wood resin 1 hexa (g.) ui rupture ture Series 1 Temp.-mo1d 40 8 2 10 10, 000 50 Series 2 250 F 2, 703 300 F 600 350 F 2, 640 Time 40 8 2 325 10,000 50 2 mm... 3, 600 313 7.1 5min 3,500 310 7.9 10 min 4,140 285 7. 6 min--. 2, 820 218 9.0 Resin 40 2 10 325 10,000 50 8 g- 3,100 213 7.1 6 g 3,000 255 6.1 4 g 2, 820 250 1. 3 2 g 1, 650 260 3. 9 Hexa 40 6 10 325 10,000 8 46 2 g 3,370 275 6.0 1. 5 2, 690 275 5. 8 1. 0 2, 760 252 5. 6 0.5 g--- 2, 400 265 5. 6 0 g. ,310 300 5. 3 Weight chg. to 40 s 2 10 325 10,000 g 940 30-28- 4= 1. 6 mold. g- 1,820 258 4036.4= 3. 6 50 g- 3,480 203 5041.7= 8.3 g 5,170 183 60-48 2 Size of wood dust-.- 40 6 2 10 325 10, 000 50 Coarse medium (avg) 2, 950 250 6.0 fine. 2, 880 260 6. 1 3, 530 280 5. 8 Resin melt point 40 6 2 10 325 10, 000 50 #217 100 C 3,000 150 6.2 #20013 100 G.. ,420 193 6.3 #209 92 C 2, 900 191 6. 3 #200A 84 C- 2, 880 240 6. 7 #219 80 C 3, 000 255 6. 1

1 Resin #219, Ring & Ball M.P. 80 C. 2 Variable: see column at right for numbers. 3 Plus hexa.

30% by weight, preferably from 15 to 25% by weight.

The filler material employed in making artificial board may be wood, paper, straw, corn stalks, bagasse, nut shells, and other fibers from naturally occurring and man-made sources. A particularly suitable material is sawdust. The latter has not been popular for making hardboard because the fibers are too short. Commercial hardboards contain fillers made by special treatment of wood. We have found that sawdust is well suited as an extender for petroleum resin when it is used in conjunction with hexamethylenetetramine. We have also found that paper fiber such as shredded newsprint alone or in conjunction with sawdust provides a high strength hardboard.

The sawdust may be coarse, medium, fine, or mixed.

The filler is present in amounts ranging from 50 to 95% by weight, preferably from to 85% by weight, based on the total mixture.

Hexamethylenetetramine is present in amounts rang- The table shows that without hexamethylenetetramine the modulus of rupture (28 C.) was 2,310. This value increased to 3,370 with the addition of 2.0 gms. of hexamethylenetetramine. This was an unexpected development in View of the following data which shows that hexamethylenetetramine has no effect on the res n alone.

Eight grams of petroleum resin similar to those disclosed in Table I were mixed with two grams of hexamethylenetetramine and heated to 325 F. at 800 p.s.i.g. for 10 minutes. The same treatment was given to the resin alone. Ring and ball softening points of the two samples were obtained. The resin containing hexamethylenetetrarnine had a softening point of 94 C. and the plain resin had a softening point of 92 C. which indicates that the hexamethylenetetr-amine has little or no eifect on the petroleum resin.

Table III shows the efiect of mixing various amounts of sawdust and paper with the resin and hexamethylenetetramine. With 20 weight percent sawdust and 80% paper, a modulus of rupture of over 6000 was achieved.

TABLE III Efiect of Varying Wood to Paper Fiber Content of Pressed Hardboard Grams Grams Grams Grams Wood/ Mod. of rupwood paper resin hexa paper ture at 28 0.

powder fibre 40 0 0 0 100/0 750 40 0 0 2 100/0 1,000 40 0 8 2 100/0 3,100 36 4 s 2 90/10 4, 000 32 s 8 2 80/20 5,300 24 16 8 2 60/40 5,350 16 24 s 2 40/60 5,550 8 32 s 2 20/80 6,850; 1 7, 400 4 36 s 2 /90 7,650 0 40 s 2 0/100 6,200 0 40 0 2 0/100 2, 000 0 40 0 0 0/100 1,850

1 Repeat run.

Various modifications of the invention such as blending of resins, the employment of fireproofing agents and the formation of the artificial board into floor tiles and the like will be apparent from the foregoing description to those skilled in the art.

We claim:

1. An artificial board consisting essentially of a heated and compressed mixture of from 5.0 to 30.0 wt. percent of petroleum resin prepared by the condensation of an aldehyde and a hydrocarbon fraction containing aromatic hydrocarbons boiling in the range of from about 200 F. to about 650 F. in the presence of an acid catalyst, at condensation conditions suitable for the particular aldehyde, hydrocarbon fraction and catalyst employed,

6 from 75.0 to 95.0 wt. percent of a cellulosic filler and from 0.1 to 6.0 wt. percent hexamethylenetetramine.

2. An artificial board according to claim 1 in which the cellulosic filler is sawdust.

3. An artificial board according to claim 1 in which the cellulosic filler is ground paper.

4. An artificial board according to claim 1 in Which the cellulosic filler is a mixture of ground paper and sawdust.

5. A process for making artificial board which comprises heating and pressing a mixture of from about 0.1 to about 6.0 Wt. percent hexamethylenetetramine and from about 75.0 to about 95.0 wt. percent of a cellulosic filler with from about 5.0 to about 30.0 wt. percent petroleum resin prepared by condensing a hydrocarbon fraction boiling in the nange of from about 200 F. to about 650 F. containing aromatic hydrocarbons with formaldehyde in the presence of an acid catalyst, at a temperature in the range of 200 C. and a pressure in the range of atmospheric to 300 p.s.i.\g., and separating the said resin.

6. The artificial board produced by the process of claim 5.

References Cited in the file of this patent UNITED STATES PATENTS 2,054,243 Cowdery Sept. 15, 1936 2,397,398 Badertscher et al Mar. 26, 1946 2,418,293 Farber Apr. 1, 1947 OTHER REFERENCES Ellis: Chemistry of Synthetic Resins, volume 1, published by Reinhold Publishing Company, 1935, page 695. 

1. AN ARTIFICIAL BOARD CONSISTING ESSENTIALLY OF A HEATED AND COMPRESSED MIXTURE OF FROM 5.0 TO 30.0 WT. PERCENT OF PETROLEUM RESIN PREPARED BY THE CONDENSATION OF AN ALDEHYDE AND A HYDROCARBON FRACTION CONTAINING AROMATIC HYDROCARBONS BOILING IN THE RANGE OF FROM ABOUT 200*F. TO ABOUT 650*F. IN THE PRESENCE OF AN ACID CATALYST, AT CONDENSATION CONDITIONS SUITABLE FOR THE PARTICULAR ALDEHYDE, HYDROCARBON FRACTION AND CATALYST EMPLOYED, FROM 75.0 TO 95.0 WT. PERCENT OF A CELLULOSIC FILLER AND FROM 0.1 TO 6.0 WT. PERCENT HEXAMETHYLENETETRAMINE. 